Suzuki EN125-2A, Service Manual

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7-3 SERVICING INFORMATION
Complaint
Engine lacks power.
Engine overheats.
Symptom and possible causes Remedy
1. Loss of valve clearance.
2. Weakened valve springs.
3. Valve timing out of adjustment.
4. Worn piston ring or cylinder.
5. Poor seating of valves.
6. Fouled spark plug.
7. Worn rocker arms or its shafts.
8. Sprak plug gap incorrect.
9. Clogged jets in carburetor.
10. Clogged air cleaner element.
11. Too much engine oil.
12. Suck air intake pipe.
Adjust.
Replace.
Adjust.
Replace.
Repair.
Clean or replace.
Replace.
Adjust or replace.
Clean.
Clean.
Drain out excess oil.
Retighten or replace.
1. Heavy carbon deposit on piston crown.
2. Not enough oil in the engine.
3. Defective oil pump or clogged oil circuit.
4. Air leak from intake pipe.
5. Use of incorrect engine oil.
Clean.
Add oil.
Repair or clean.
Retighten or replace.
Change.
Complaint
Trouble with starting.
Idling or low-speed
trouble.
Medium or high-speed
trouble.
Overflow and fuel
level fluctuations.
Symptom and possible causes Remedy
Clean.
Clean.
Check starter body and carburetor
for tightness, adjust and replace
gasket.
Check and adjust.
1. Needle valve is worn or damaged.
2. Spring in needle valve is broken.
3. Float is not working properly.
4. Foreign matter has adhered to needle valve.
1.Starter jet is clogged.
2.Starter pipe is clogged.
3. Air leaking from a joint between starter body and carburetor.
4.Starter plunger is not operating properly.
Replace.
Replace.
Check and adjust.
Clean.
Check and clean.
Check and clean.
Check throttle valve for operation.
Check and clean.
CARBURETOR
1. Pilot jet, pilot air jet are clogged or loose.
2. Pilot outlet or bypass is clogged.
3. Starter plunger is not fully closed.
1. Main jet or main air jet is clogged.
2. Needle jet is clogged.
3. Throttle valve is not operating properly.
4. Filter is clogged.
Check and clean.
Check and clean.
Check and adjust.
Complaint
No sparking or poor
sparking.
Spark plug soon become
fouled with carbon.
Symptom and possible causes Remedy
Replace.
Replace.
Replace.
Adjust carburetor.
Adjust carburetor.
Change.
Clean.
Replace by hot type plug.
1. Defective ignition coil.
2. Defective spark plug.
3. Defective pick up coil or ignitor unit.
1. Mixture too rich.
2. Idling speed set too high.
3. Incorrect gasoline.
4. Dirty element in air cleaner.
5. Spark plug too cold.
ELECTRICAL